Ballotpedia Python API Docs | dltHub

Build a Ballotpedia-to-database pipeline in Python using dlt with AI harness support for Claude Code, Cursor, and Codex.

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Ballotpedia provides geographic and bulk data APIs for accessing election, ballot measure, and other political data via HTTP GET and POST requests. The REST API base URL is https://api4.ballotpedia.org/ or https://api.ballotpedia.org/ and all requests require an x-api-key header.

dlt is an open-source Python library that handles authentication, pagination, and schema evolution automatically. dlthub provides AI context files that enable code assistants to generate production-ready pipelines. Install with uv add "dlt[hub]" and start loading Ballotpedia data in under 10 minutes.


What data can I load from Ballotpedia?

Here are some of the endpoints you can load from Ballotpedia:

ResourceEndpointMethodData selectorDescription
election_dates/data/election_dates/listGETReturns election dates based on filtering parameters.
elections_by_state/data/elections_by_stateGETReturns candidates, ballot measures, and races for a given state/date.
ballot_measures/data/ballot_measuresGETdistrictsReturns ballot measures grouped by district for a state/date.
election_dates_measures/data/election_dates/ballot_measuresGETelection_datesReturns states and dates with ballot measures for a year.
query_list/getQueryListGETLists available bulk data sets.

How do I authenticate with the Ballotpedia API?

All requests require an 'x-api-key' HTTP header containing the user's active API key. Some endpoints also require a 'Content-Type: application/json' header.

1. Get your credentials

Ballotpedia's data services are managed through their client portal at https://clients.ballotpedia.org/. To obtain API credentials, you must contact Ballotpedia's data sales staff to purchase access, after which you will be provided with an API key for your account.

2. Add them to .dlt/secrets.toml

[sources.ballotpedia_source] x_api_key = "your_api_key_here"

dlt reads this automatically at runtime — never hardcode tokens in your pipeline script. For production environments, see setting up credentials with dlt for environment variable and vault-based options.


How do I set up and run the pipeline?

Set up a virtual environment and install dlt:

uv init uv add "dlt[hub]"

1. Install the dlt AI harness:

uv run dlthub ai init --agent <your-agent> # <agent>: claude | cursor | codex

This installs project rules, a secrets management skill, appropriate ignore files, and configures the dlt MCP server for your agent. Learn more →

2. Install the rest-api-pipeline toolkit:

uv run dlthub ai toolkit install rest-api-pipeline

This loads the skills and context about dlt the agent uses to build the pipeline iteratively, efficiently, and safely. The agent uses MCP tools to inspect credentials — it never needs to read your secrets.toml directly. Learn more →

3. Start LLM-assisted coding:

Use /find-source to load data from the Ballotpedia API into DuckDB.

The rest-api-pipeline toolkit takes over from here — it reads relevant API documentation, presents you with options for which endpoints to load, and follows a structured workflow to scaffold, debug, and validate the pipeline step by step.

4. Run the pipeline:

uv run python ballotpedia_pipeline.py

If everything is configured correctly, you'll see output like this:

Pipeline ballotpedia_pipeline load step completed in 0.26 seconds 1 load package(s) were loaded to destination duckdb and into dataset ballotpedia_data The duckdb destination used duckdb:/ballotpedia.duckdb location to store data Load package 1749667187.541553 is LOADED and contains no failed jobs

Inspect your pipeline and data:

uv run dlthub show

This opens the Pipeline Dashboard where you can verify pipeline state, load metrics, schema (tables, columns, types), and query the loaded data directly.


Python pipeline example

This example loads getQueryList and getQueryResults from the Ballotpedia API into DuckDB. It mirrors the endpoint and data selector configuration from the table above:

import dlt from dlt.sources.rest_api import RESTAPIConfig, rest_api_resources @dlt.source def ballotpedia_source(api_key=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://api4.ballotpedia.org/ or https://api.ballotpedia.org/", "auth": {"type": "api_key", "api_key": api_key, "name": "x-api-key", "location": "header"}, }, "resources": [ {"name": "election_dates_list", "endpoint": {"path": "data/election_dates/list"}}, {"name": "ballot_measures", "endpoint": {"path": "data/ballot_measures"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="ballotpedia_pipeline", destination="duckdb", dataset_name="ballotpedia_data", ) load_info = pipeline.run(ballotpedia_source()) print(load_info)

To add more endpoints, append entries from the resource table to the "resources" list using the same name, path, and data_selector pattern.


How do I query the loaded data?

Once the pipeline runs, dlt creates one table per resource. You can query with Python or SQL.

Python (pandas DataFrame):

import dlt data = dlt.pipeline("ballotpedia_pipeline").dataset() sessions_df = data.election_dates_list.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM ballotpedia_data.election_dates_list LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("ballotpedia_pipeline").dataset() data.election_dates_list.df().head()

See how to explore your data in marimo Notebooks and how to query your data in Python with dataset.


What destinations can I load Ballotpedia data to?

dlt supports loading into any of these destinations — only the destination parameter changes:

DestinationExample value
DuckDB (local, default)"duckdb"
PostgreSQL"postgres"
BigQuery"bigquery"
Snowflake"snowflake"
Redshift"redshift"
Databricks"databricks"
Filesystem (S3, GCS, Azure)"filesystem"

Change the destination in dlt.pipeline(destination="snowflake") and add credentials in .dlt/secrets.toml. See the full destinations list.


Next steps

Continue your data engineering journey with the other toolkits of the dltHub AI harness:

  • data-exploration — Build custom notebooks, charts, and dashboards for deeper analysis with marimo notebooks.
  • dlthub-platform — Deploy, schedule, and monitor your pipeline in production.
uv run dlthub ai toolkit install data-exploration uv run dlthub ai toolkit install dlthub-platform

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